A comparative study of ferrocenyl carboxylate cadmium(II) complexes prepared by two different synthetic methods

Reaction of ferrocenyl carboxylate H2bfcs with Cd(Ac)2 · 2H2O (H2bfcs = 1,1′-bis(3-carboxy-1-oxopropyl)ferrocene) gives the mononuclear tetrahydrate precursor Cd(Hbfcs)2(H2O)4 (1). Investigation on the substitution reactions of 1 with imidazole or 2,2′-bpy afforded two one-dimensional (1D) complexes {[Cd2(bfcs)2(C3H4N2)6] · 4H2O}n (2) and {[Cd(bfcs)(2,2′-bpy)(H2O)] · 2H2O}n (4) (2,2′-bpy = 2,2′-bipyridine), respectively. However, the one-step reactions of H2bfcs, Cd(Ac)2 · 2H2O with imidazole or 2,2′-bpy result in the formation of two different 1D complexes {[Cd(bfcs)(C3H4N2)2] · CH3OH · 2H2O}n (3) and [Cd(bfcs)(CH3OH)]n (5). It can be seen from the results that applying different synthetic routes produce dissimilar complexes from however the same materials and under the same reaction conditions. In addition, investigations of differential pulse voltammetry of these four 1D complexes indicate that their half-wave potentials are slightly higher than that of H2bfcs.